In this type of installation, the unstacking magazine is conventionally equipped with members for separating articles individually, said members being mounted at a front end of the magazine and being commonly referred to as an "unstacking head". The magazine is also equipped with retaining means for retaining the articles in one or more stacks, said retaining means being coupled to drive means to move the articles forwards along the magazine towards its head.
By way of example, the unstacking head may be of the type having a suction cup movably mounted to rock so as to come into contact with and take hold of the facing end article in the stack, and to reciprocate in translation so as to take the held article away from the magazine and release it, and then to return to the front of the stack. This head is adapted to the characteristics of the articles to enable them to be taken one-by-one without being damaged. Its positioning and/or its rocking may be controlled by detecting the format and/or disposition of the successive end articles to be removed.
The magazine feeds the head as and when articles are removed. The retaining means for retaining the articles are of the type having panels coupled to the drive means. When unstacking relatively uniform articles, these panels remain fixed to the drive means which are constituted by an endless conveyor or chain. The panels are driven in an active position from the rear of the magazine to its front, to move the articles forwards, and the panels are retracted in front of the head from where they are recycled in an inactive position back to the rear of the magazine. Instead of using such panels spread out in this way around a closed circuit, it is preferable to use removable panels on the magazine, in particular when the articles are very varied.
French Patent Application 89 13605 filed in the name of the Applicant describes such a magazine having removable panels. These panels are installed by hand and they are coupled to the drive means in a loading zone on the rear portion of the magazine, from where they move the articles loaded onto this zone forwards up to the head. They separate from the drive means in front of the head and are guided to and received in a panel storage zone provided on one side of the front end portion of the magazine.
In both of these types of magazine, and in particular in magazines having removable panels, the articles are loaded onto the rear zone of the magazine by hand. This hand loading of articles is not very convenient. It suffers from certain difficulties, especially when the articles are varied and relatively slippery, and/or when the preceding stack has already advanced a considerable distance along the magazine and is relatively far away from the supply of articles, which supply is generally in the form of a bin on a work surface at the rear end of the magazine. Among the difficulties and problems encountered, the following should be mentioned in particular:
it is difficult to keep the stack together between being removed from the supply and being deposited behind the panel retaining the previous stack and moving it forwards; and
building up a new stack by removing small batches from the supply requires the batches that have already been loaded to be held substantially vertical with one hand, while further batches are being removed with the other hand.
Furthermore, such difficult manipulation is not very compatible with the time restrictions imposed on an operator in charge of feeding a plurality of magazines and checking that they are operating correctly.
The object of the present invention is to avoid these problems by loading the articles directly and quickly from storage bins onto the unstacking magazine, to facilitate the work of the operator, to improve the comfort and quality of the work, and to organize operator time better.